Postemergence Herbicide Options for Virginia Buttonweed (Diodia virginiana) Control

• Published in: Weed technology Vol. 14; no. 2; pp. 246 - 251
• Main Authors: KELLY, S. T, COATS, G. E
• Format: Journal Article
• Language: English
• Published: Lawrence, KS Weed Science Society of America 01-04-2000
• Subjects: Acid soils; Agroforestry; Amines; Biological and medical sciences; Cantons; Chemical control; Dimethylamines; Esters; Field experiments; Fundamental and applied biological sciences. Psychology; Herbicides; Infestation; Parasitic plants. Weeds; Phytopathology. Animal pests. Plant and forest protection; Turf grasses; Weeds; Auxin; Systemic; Field experiment; Dose activity relation; Dicotyledones; Angiospermae; Rubiaceae; Alkanoic acid; Ultisols; Greenhouse study; Sandy loam soil; Weed; 2,4-D; Treatment efficiency; Pesticides; Alfisols; Postemergence; Herbicide; Propionic acid(2-aryloxy); Silt loam soil; Sulfonylureas; Spermatophyta; Phytohormone; Aryloxyacetic acids; Chemical weed control
• ISSN: 0890-037X; 1550-2740
• DOI: 10.1614/0890-037X(2000)014[0246:PHOFVB]2.0.CO;2

Combinations of 0 to 1,120 g ae/ha 2,4-D plus 0 to 42 g ai/ha metsulfuron were evaluated in both field and greenhouse experiments. Addition of metsulfuron to 2,4-D increased Virginia buttonweed (Diodia virginiana) fresh weight reduction in the greenhouse compared with 2,4-D alone, but reduction in fresh weight was not different from 32 g/ha or more of metsulfuron applied alone. In field experiments 5 wk after treatment (WAT), combinations of metsulfuron and 2,4-D did not control Virginia buttonweed greater than 32 g/ha or more of metsulfuron alone. No synergism for the combinations was observed. Field experiments conducted from 1991 to 1993 evaluated three-way combinations of herbicides for Virginia buttonweed control. Treatments included: 2,4-D plus mecoprop plus dicamba (five herbicide premixes), 2,4-D plus dichlorprop plus dicamba, 2,4-D plus MCPA plus dichlorprop, mecoprop plus MCPA plus dichlorprop, or 2,4-D plus mecoprop plus dichlorprop. Combinations containing at least 688 g/ha 2,4-D provided the most consistent Virginia buttonweed control 2 WAT. By 7 WAT, control was no more than 60% for any treatment. A separate experiment evaluated the effects of repeated applications of two- or three-way herbicide mixtures applied at least 5 wk apart when ground cover regrowth was 25%. Treatments included: 2,4-D plus dichlorprop plus dicamba ester, 2,4-D plus mecoprop plus dicamba amine, 2,4-D plus dichlorprop amine, or 2,4-D plus dichlorprop ester. Ground cover 1 yr following application of sequential treatments was 35% or less compared to 65% in the nontreated control. Following 2 yr of herbicide application, ground cover in the treated plots was 28% or less.